arch/powerpc/kernel/align.c

Source file repositories/reference/linux-study-clean/arch/powerpc/kernel/align.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/kernel/align.c
Extension
.c
Size
8473 bytes
Lines
356
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct aligninfo {
	unsigned char len;
	unsigned char flags;
};


#define INVALID	{ 0, 0 }

/* Bits in the flags field */
#define LD	0	/* load */
#define ST	1	/* store */
#define SE	2	/* sign-extend value, or FP ld/st as word */
#define SW	0x20	/* byte swap */
#define E4	0x40	/* SPE endianness is word */
#define E8	0x80	/* SPE endianness is double word */

#ifdef CONFIG_SPE

static struct aligninfo spe_aligninfo[32] = {
	{ 8, LD+E8 },		/* 0 00 00: evldd[x] */
	{ 8, LD+E4 },		/* 0 00 01: evldw[x] */
	{ 8, LD },		/* 0 00 10: evldh[x] */
	INVALID,		/* 0 00 11 */
	{ 2, LD },		/* 0 01 00: evlhhesplat[x] */
	INVALID,		/* 0 01 01 */
	{ 2, LD },		/* 0 01 10: evlhhousplat[x] */
	{ 2, LD+SE },		/* 0 01 11: evlhhossplat[x] */
	{ 4, LD },		/* 0 10 00: evlwhe[x] */
	INVALID,		/* 0 10 01 */
	{ 4, LD },		/* 0 10 10: evlwhou[x] */
	{ 4, LD+SE },		/* 0 10 11: evlwhos[x] */
	{ 4, LD+E4 },		/* 0 11 00: evlwwsplat[x] */
	INVALID,		/* 0 11 01 */
	{ 4, LD },		/* 0 11 10: evlwhsplat[x] */
	INVALID,		/* 0 11 11 */

	{ 8, ST+E8 },		/* 1 00 00: evstdd[x] */
	{ 8, ST+E4 },		/* 1 00 01: evstdw[x] */
	{ 8, ST },		/* 1 00 10: evstdh[x] */
	INVALID,		/* 1 00 11 */
	INVALID,		/* 1 01 00 */
	INVALID,		/* 1 01 01 */
	INVALID,		/* 1 01 10 */
	INVALID,		/* 1 01 11 */
	{ 4, ST },		/* 1 10 00: evstwhe[x] */
	INVALID,		/* 1 10 01 */
	{ 4, ST },		/* 1 10 10: evstwho[x] */
	INVALID,		/* 1 10 11 */
	{ 4, ST+E4 },		/* 1 11 00: evstwwe[x] */
	INVALID,		/* 1 11 01 */
	{ 4, ST+E4 },		/* 1 11 10: evstwwo[x] */
	INVALID,		/* 1 11 11 */
};

#define	EVLDD		0x00
#define	EVLDW		0x01
#define	EVLDH		0x02
#define	EVLHHESPLAT	0x04
#define	EVLHHOUSPLAT	0x06
#define	EVLHHOSSPLAT	0x07
#define	EVLWHE		0x08
#define	EVLWHOU		0x0A
#define	EVLWHOS		0x0B
#define	EVLWWSPLAT	0x0C
#define	EVLWHSPLAT	0x0E
#define	EVSTDD		0x10
#define	EVSTDW		0x11
#define	EVSTDH		0x12
#define	EVSTWHE		0x18
#define	EVSTWHO		0x1A
#define	EVSTWWE		0x1C
#define	EVSTWWO		0x1E

/*
 * Emulate SPE loads and stores.
 * Only Book-E has these instructions, and it does true little-endian,
 * so we don't need the address swizzling.
 */
static int emulate_spe(struct pt_regs *regs, unsigned int reg,
		       ppc_inst_t ppc_instr)
{
	union {
		u64 ll;
		u32 w[2];
		u16 h[4];
		u8 v[8];
	} data, temp;
	unsigned char __user *p, *addr;
	unsigned long *evr = &current->thread.evr[reg];
	unsigned int nb, flags, instr;

Annotation

Implementation Notes